document.write( "Question 846438: Make a conjecture about the following results:\r
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\n" ); document.write( "\n" ); document.write( "Square root of 3 3/8=3 square root of 3/8.\r
\n" ); document.write( "\n" ); document.write( "Try to prove your conjecture.
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Algebra.Com's Answer #513622 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
Square root of 2 2/3=2 square root of 2/3.
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document.write( "\"sqrt%282%262%2F3%29\"\"%22%22=%22%22\"\"sqrt%288%2F3%29\"\"%22%22=%22%22\"\"sqrt%284%2A2%2F3%29\"\"%22%22=%22%22\"\"sqrt%284%2Aexpr%282%2F3%29%29\"\"%22%22=%22%22\"\"2%2Asqrt%282%2F3%29\"\r\n" );
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document.write( "\"sqrt%283%263%2F8%29\"\"%22%22=%22%22\"\"sqrt%2827%2F8%29\"\"%22%22=%22%22\"\"sqrt%289%2A3%2F8%29\"\"%22%22=%22%22\"\"sqrt%289%2Aexpr%283%2F8%29%29\"\"%22%22=%22%22\"\"3%2Asqrt%283%2F8%29\"\r\n" );
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document.write( "It's easy to see the pattern, except for the denominators, where\r\n" );
document.write( "I have put question marks below.  There is no way to determine just by\r\n" );
document.write( "inspection, a sequence for the denominators with just the first \r\n" );
document.write( "two terms, 3 and 8.  We could guess a general term for the\r\n" );
document.write( "denominators, but that would be risky business. \r\n" );
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document.write( "\"sqrt%28n%2Bn%2F%22%3F%22%29\"\"%22%22=%22%22\"\"n%2Asqrt%28n%2F%22%3F%22%29\" \r\n" );
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document.write( "Now let's let D be those denominators, \r\n" );
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document.write( "\"sqrt%28n%2Bn%2FD%29\"\"%22%22=%22%22\"\"n%2Asqrt%28n%2FD%29\"\r\n" );
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document.write( "and solve for D.  Square both sides:\r\n" );
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document.write( "\"n\"\"%22%22%2B%22%22\"\"n%2FD\" \"%22%22=%22%22\" \"n%5E2%2A%28n%2FD%29\"\r\n" );
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document.write( "\"%28nD%2Bn%29%2FD\"\"%22%22=%22%22\"\"n%5E3%2FD\"\r\n" );
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document.write( "Multiply both sides by D\r\n" );
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document.write( "\"nD%2Bn\"\"%22%22=%22%22\"\"n%5E3\"\r\n" );
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document.write( "Divide through by n\r\n" );
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document.write( "\"D%2B1\"\"%22%22=%22%22\"\"%22%22=%22%22\"\"n%5E2\"\r\n" );
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document.write( "\"D\"\"%22%22=%22%22\"\"n%5E2-1\" for n > 1\r\n" );
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document.write( "So our conjecture is found by substituting that\r\n" );
document.write( "expression for D in:\r\n" );
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document.write( "\"sqrt%28n%2Bn%2FD%29\"\"%22%22=%22%22\"\"n%2Asqrt%28n%2FD%29\"\r\n" );
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document.write( "\"sqrt%28n%2Bn%2F%28n%5E2-1%29%29\"\"%22%22=%22%22\"\"n%2Asqrt%28n%2F%28n%5E2-1%29%29\" for n > 1\r\n" );
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document.write( "To prove that we have to show that each side is non-\r\n" );
document.write( "negative (obvious) and have the same square.  We show \r\n" );
document.write( "that each side has the same square:\r\n" );
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document.write( "LEFT SIDE = \"sqrt%28n%2Bn%2F%28n%5E2-1%29%29\"\"%22%22=%22%22\"\r\n" );
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document.write( "SQUARE OF LEFT SIDE = \"n%2Bn%2F%28n%5E2-1%29\"\"%22%22=%22%22\"\"%28n%5E3-n%2Bn%29%2F%28n%5E2-1%29\"\"%22%22=%22%22\"\"n%5E3%2F%28n%5E2-1%29\"\r\n" );
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document.write( "RIGHT SIDE = \"n%2Asqrt%28n%2F%28n%5E2-1%29%29\"\r\n" );
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document.write( "SQUARE OF RIGHT SIDE = \"n%5E2%28n%2F%28n%5E2-1%29%29\"\"%22%22=%22%22\"\"n%5E3%2F%28n%5E2-1%29\"\r\n" );
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document.write( "So they have the same square and are both non-negative so the conjecture\r\n" );
document.write( "is proved.\r\n" );
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document.write( "Edwin
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